Active Fuel Management?

[Warghost]

Also remember that the "new" direct injection system will also help with fuel economy. The rumor I've heard is that this new system will create more power, therefore GM may opt to reduce the size of the pistons, which will help the fuel economy a little while keeping the 400HP range they are aiming for.

Regarding AFM, I'm not sure how to feel about it yet. I never drive on the highway and live close to work, so it would rarely help me. Personally, I'm for anything that will help at the pump, but not if it will detract from my driving experience in any way. And it's important to note that "cruising" can be considered ANY speed, when the engine is in a higher gear and therefore under less load. So, expect the AFM to be kicking in a lot more often than only on long highway trips. At 45MPH, I'm at 1500RPMs on city streets in fifth gear. Wouldn't that kick on AFM?

But, here are two things to remember:

1) Companies like Diablo and SCT make tuners that will probably (hopefully) allow AFM to be disabled, the same way that Traction Control can be disabled through the computer.

2) The post about the AFM causing someone's truck to sound like it was "missing" could be anything. It may be a very quiet miss that wouldn't be audible with Flowmasters anyway, or it may actually sound nice....perhaps like a loping idle sound, which I think I would like anyway. Especially considering FLowmasters have a weak droning sound when the engine is under light load anyway.

[TAG UR IT]

I wouldn't want AFM turned off for any reason (other than the car turning it off because I'm flooring it). AFM should kick in at 45, I agree. This should help with the city streets. It doens't need to be all on hwy to get the AFM to work.

[stovt001]

The Honda cylinder deactivation brought 6 cylinders down to 3, and to make up for the change in sound white noise that would match the sound patter back to that of the full V6 was pumped through the speakers, or something like that. Helps those inside the car, but not outside. In any case, I don't think that will be a problem here, as 4 cylinders sound very different than 3 (go drive a Geo Metro around and you'll see). So I'm sure that really, AFM will have no performance penalty. You go light on the gas, holding a steady speed, unnecessary cylinders cut off. You hit the gas, and the come back online. I've heard its actually rather seamless.

[Sick]

I don't have a problem controlling my day to day driving to keep my MPG down. I drive a 6cyl turbo right now and it isn't too bad on gas so long as I take some weight off the lead foot I've got.

That may change once I get that Camaro.

[Warghost]

Do you guys think that there would be an indicator light to show us when AFM is working? Maybe a light in the instrument cluster, like when Traction Control is on in the Mustangs.

Also, how often do you think AFM would be activated while driving in city traffic daily? Is it more of a highway thing, or always ready to turn on whenever the engine is under light load?

[$¢'s 5th Gen]

Originally Posted by Dragoneye

Sound-shmound, it'll only activate when your cruising, IF your cruising...the minute you hammer it, our lovely rumble will be right back

It will sound like a high lopping cam at 60 mph as far as hammering it, that rumble will turn into a scream quickly

[stovt001]

Originally Posted by Warghost

Do you guys think that there would be an indicator light to show us when AFM is working? Maybe a light in the instrument cluster, like when Traction Control is on in the Mustangs.

Also, how often do you think AFM would be activated while driving in city traffic daily? Is it more of a highway thing, or always ready to turn on whenever the engine is under light load?

On GM vehicles that currently use AFM, a message will appear in the DIC saying something along the lines of "4 Cyl Mode" or "8 Cyl Mode" when the AFM turns off and it goes back into normal operation. I'm sure there will be an indicator of some sort, and its form will just depend on the constraints of the dash layout.

In stop and go city driving I don't think it will engage. You'll need to hold a consistent in the upper gears for a little while before it activates. There are a couple roads near me with 45-50 mph speed limits and few stoplights and I imagine I'll use AFM mostly on those and in light traffic situations on the freeway.

[Sterling]

The active fuel management is controled by oil pressure. It has a collapsible lifter that is two pieces, allowing half the lifter to move on the cam, but not activating the rocker arm and opening the valve. The GM training rep said that if it ever does malfunction, the cylinder won't deactivate, so you don't have to worry about the engine getting stuck running on only 4 cylinders.

[September]

We had an article in a UK Sunday newpaper this weekend. Good article regarding an active fuel management system which will give even the V8 around 30mpg!

Do we think it will have 2+2 seating? Thats a big point for me and whether or not i can buy one as i have a 4.5 year old now (he'll be almost 6 when it comes out!)

[Mr. Wyndham]

Do we all remember when the concept was first shown at NAIAS...and then they said "We'd be brain dead not to build it"?

A few days after GM started talking about it. And while standing in front of the Concept - which is to be the "High-end" model for 30,000, a GM exec mentioned that with AFM this could get 30+ mpg Hwy (which, btw - is the same as my Cobalt right now ....wait....).

Anyways, do y'all think he was talking about the V8 trim? or a V6 with AFM? Because...I don't quite understand, exactly how they can beat out a V8 model with 30-31 mpg highway....what would the "economy" V6 have to be...35-36mpg hwy?!?!?! That would be friggin' ridiculous (in a good way)

[September]

I'm thinking about the fuel cost here in the UK - currently at £1.03 - £1.05 per litre!!

So for me it could be a good thing as it'd be my 'first car' with a second bigger one (a diesel) for other occasions!

[octane_n_veins]

All Active Fuel Management does is “When load demands increase, such as when vehicle accelerates or travels uphill, cylinders are activated to provide 8-cylinder operation. The powerful, 32 bit engine control module triggers cylinder deactivation based on inputs from vehicle sensors – making deactivation almost undetectable.” – Strait from GM definition.
I’m curious to know is with AFM will the Camaro have VVT – Variable Valve Timing?

[Mr. Wyndham]

I love reading this over, and over again (also from GM):

"Further, the savings reflected in EPA numbers may not account for AFM’s full impact. Owners who primarily travel long distances at steady speeds will see substantially greater fuel-economy improvements. "

[$¢'s 5th Gen]

Originally Posted by Dragoneye

....what would the "economy" V6 have to be...35-36mpg hwy?!?!?! That would be friggin' ridiculous (in a good way)

That should be easy this day in age. My 96 V6 got 29 mpg hwy